Describe an activity to show that air flows from a region of high pressure to a region of low pressure.
Take two similar balloons made of thin rubber and a drinking straw.
Insert one end of the straw into one uninflated balloon and secure it. Inflate the second balloon and hold its mouth closed. Insert the free end of the straw into the inflated balloon and secure it.
When released, air flows from the inflated balloon (high pressure) to the uninflated balloon (low pressure). The inflated balloon shrinks while the uninflated balloon expands.
The flow continues until both balloons reach approximately equal size, demonstrating that air flows from high to low pressure regions until pressure equalizes.
Explanation
This activity is described in Activity 6.5 of the chapter. The chapter states: 'The air pressure in the inflated balloon is higher than that in the uninflated balloon. As a result, some air moves from the inflated balloon to the uninflated balloon, resulting in changes in the size of both the balloons.'
Solution Steps
Take two similar balloons made of thin rubber and a drinking straw
Insert one end of the straw into one uninflated balloon and secure it
Inflate the second balloon and hold its mouth closed
Insert the free end of the straw into the inflated balloon and secure it
When released, observe air flowing from the inflated balloon (high pressure) to the uninflated balloon (low pressure)
The inflated balloon shrinks while the uninflated balloon expands
Flow continues until both balloons reach approximately equal size, demonstrating that air flows from high to low pressure regions until pressure equalizes